It is widely known that, in the reactor type with a fixed catalyst bed, it is necessary to distribute as homogeneously as possible the gas phase as well as the liquid phase.
It is also necessary to provide the most even and uniform distribution possible of these two phases all along the frontal section of this reactor so as to optimize gas-liquid contact in the reactor and to operate the various zones of this reactor in a substantially identical manner.
As it is already known from document U.S. Pat. No. 3,441,418, this distribution can be achieved by a distribution plate equipped with vertical chimneys and perforations whose purpose is to obtain a substantially uniform distribution of the gas phase and of the liquid phase over the entire section of a reactor that is in most cases of cylindrical shape.
This type of distribution plate also allows to distribute the gas phase through the perforations of the plate and the liquid phase through the chimneys.
U.S. Pat. No. 6,123,323 describes a distribution device that can be used in an ascending flow in a reactor supplied with a mixture of liquid and gas.
This device is made up of a distribution plate occupying all or part of the entire section of the reactor delimiting a volume wherein the gas and the liquid are separated. The gas then flows through orifices distributed over the entire section of the plate. The liquid flows separately through vertical chimneys running through the plate and extending below the liquid/gas interface or through fractions of the reactor section that are not covered by the plate.
This reactor, which is supplied with gas and liquid through a line located in the bottom of the enclosure, is technically interesting but it however involves quite considerable drawbacks.
In fact, operation is not optimized because the gas is poorly dispersed over the cross-section of the reactor, and a gas column generally rises at the centre thereof. This disturbs the gas-liquid interface below the distribution plate and leads to a poor gas distribution below the plate.
Furthermore, gas can possibly enter the chimneys in an unwanted manner. In case of a gas column, this results in a poor gas distribution with the presence of a larger proportion of this gas in the central zone of the plate.
Moreover, the gas disengagement thus creates significant disturbances that can induce flow pulsations and locally unbalance the gas distribution.
The present invention aims to overcome the aforementioned drawbacks by means of a catalyst bed reactor comprising a distribution plate that allows to obtain even distribution of the gas phase all along the section of the reactor without disturbing the liquid phase distribution, even in case of a gas-liquid interface disturbance.